Plants require water, and to this end the owners of flower pots holding plants periodically water them at the surface. Applying the correct amount of water to a flower pot is a near-to-impossible task, being impacted not only by the condition of the soil in the pot, but also by the particular plant's needs which may further vary by size, ambient temperature and humidity, etc. Applying too little water may result in wilting or other leaf defects such as brown spots, yellow spots and dry and brittle leaves, or even drying up of the plant, or at least stunting of its growth, or hurting its flowering as by bud drop. Applying too much water can result in unwanted flooding of household areas if flower pots with bottom drains are utilized, or in drowning or at least disease conditions such as crown or root rot or mildew, if bottom-drainless pots are utilized.
Applying even the right amount of water does not result in trouble free gardening. That is because watering from the top causes soil in a flower pot to harden or seem baked, thereby impeding the flow of water (percolation) to the bottom and around the roots of the potted plant. To minimize this problem, flower-pot constructions have been employed which enable capillary watering of the soil from the bottom. This has been done with both bottom-drain and bottom-drainless pots.
Bottom-drainless pots are preferred because of the reduced likelihood of unwanted flooding of household areas. Typically, a bottom-drainless pot is formed with a reservoir on the bottom, and tubes are employed to insert and/or remove water from the reservoir. Usually water is removed through the tubes by tilting the flower pot to where the water runs out through the drain tube under the influence of gravity.
Unfortunately, tilting a flower pot to drain a reservoir involves at least two risks. One is that loose soil in the top of the flower pot will roll out and fall in areas where it is not desired. The other is that the entire soil mass and plant will fall out of the pot as the pot is tilted to a point where the reservoir water runs out, a point at which the bottom side of the flower pot slopes downward and outward and the soil mass can slide down the slick side of the pot and onto the floor, injuring the plant in the process too.